Nutplates and screws

[William Slaughter]

It's the rough surface finish left by the phosphate coating. Run a hardened capscrew lubed with boelube in and out of the nutplate before installation. This smooths up the thread surface without removing metal as a tap would, thus preserving the self-locking feature. I do them in batches with my electric screwdriver. Of course this process can be used on nutplates already in place.

[Pat Falley]

JIS is Japanese Industrial Standard. They are similar to phillips heads, but have a little different angle.
The preferred solution would be to not replace AN screws, but to replace the JIS screwdriver.

[jacoby]

Originally Posted by msmst25

Thanks for the input. I don't remember reading anything about the locking feature of the nutplates. I ordered some Boelube and now that I know that they are supposed to be reasonably tight, I don't have to worry that I'm using the wrong parts together.

FWIW, every fastener in the airframe has some sort of locking feature. Nutplates have a bit of squeeze on them for a mechanical lock. Bolts are locked with nylock nuts or metal locking nuts or castellated nuts with a cotter pin. Rod ends have a jam nut. And safety wire on top of that in some cases and on hinge pins.

[bobnoffs]

it's not unheard of to get a nutplate that won't thread. i clamp a screw in a vise and thread each lubed nutplate on it before i install. much easier than finding it bad after it's riveted in place.

[Wunderon]

Originally Posted by bobnoffs

it's not unheard of to get a nutplate that won't thread. i clamp a screw in a vise and thread each lubed nutplate on it before i install. much easier than finding it bad after it's riveted in place.

+1 whatever you do, check the nutplates before you rivet them on lol.